Currently, conventional luminaires (i.e. lighting units) for road illumination include HPS or MHI light bulb fixtures mounted to the top of a vertical mounting pole. These luminaires are very energy inefficient compared to state of the art light emitting diode (LED) luminaires. LEDs last longer, and consume much less power. Many communities are replacing conventional luminaires with LED luminaries. However, there are numerous conventional luminaire models and associated pole mounting hole configurations, which can vary widely by brand and/or by region. As illustrated in FIG. 1, most conventional luminaire designs require the mounting pole 2 to have upper and lower mounting holes 4 and 6, with a conduit hole 8 therebetween (through which the power lines run).
One problem with designing LED luminaires for replacing conventional luminaires is that different conventional luminaire models have different spacing configurations for the mounting and conduit holes. Specifically, the distance A between the two mounting holes 4/6, and the distance B between the lower mounting hole 6 and the conduit hole 8, vary among the different conventional models. Therefore, no single LED luminaire with any given mounting hole and conduit hole spacing configuration would be compatible with all the various hole spacings found on existing mounting poles. The table in FIG. 2 illustrates numerous examples of mounting hole spacing configurations among the more popular conventional luminaire models. In addition, some of the conventional luminaires are configured to mount to round mounting poles, while others are configured to mount to square mounting poles (i.e. mounting poles that have a flat mounting surface). Therefore, one conceivably could need as many as 32 different LED luminaire designs just to accommodate the replacement of those conventional luminaire models identified in FIG. 2. One alternative is to provide a single LED luminaire mounting hole configuration, and drill new holes into the mounting pole during each conventional luminaire replacement. However, modifying the mounting pole with each luminaire replacement is time consuming and costly, especially given that the working area is located at the top of a mounting pole high above the road.
There is a need for an LED luminaire design that is compatible with multiple mounting hole configurations.